"The severe thunderstorm 15 km northeast of Duchess has weakened slightly. The storm continues to move east at 20 km/h," said an Alberta Emergency Alert issued at 8:56 p.m. MT.

"The potential threat for a tornado therefore has since diminished. This thunderstorm does continue to remain strong with a potential to produce hail, heavy rain and strong winds."

An alert was also issued for a tornado earlier this evening for a storm tracking east across southern Alberta from Hussar to the hamlet of Gem.

Environment Canada says if residents see threatening weather they should take cover in a sturdy permanent building or underground. It says vehicles, mobile homes, cottages, boats and any tents or trailers are not safe.